Slide projector

ABSTRACT

A slide projector wherein a reciprocable slide changer alternately transports lowermost slides from a centrally located tray to two projecting stations by moving the slides in a first plane which is parallel to the common plane of the projecting stations. Springs cause the thus transported slides to move from the first into the second plane and clamp the slides in registry with the respective stations. An evacuating device is reciprocable in response to reciprocation of the slide changer to remove slides from stations which are about to receive fresh slides and to transport the thus removed slides into a collecting receptacle wherein the slides are stacked in the same order in which they are being removed from the tray.

United States Patent Inventor Appl. No.

Filed Patented Assignee Priority Karl Deeg Unterhaching, Germany SLIDEPROJECTOR 13 Claims, 2 Drawing Figs.

US. Cl.....

Int. Cl

G03b 23/14 Field of Search 353/112, 113, Ill, 116, 114,94, 103, 89, 86,90, 92

[5 6] References Cited UNITED STATES PATENTS 3,264,937 8/1966 Antos353/112 Primary Examiner-Harry N. Haroian Att0meyMichael S. StrikerABSTRACT: A slide projector wherein a reciprocable slide changeralternately transports lowermost slides from a centrally located tray totwo projecting stations by moving the slides in a first plane which isparallel to the common plane of the projecting stations. Springs causethe thus transported slides to move from the first into the second planeand clamp the slides in registry with the respective stations. Anevacuating device is reciprocable in response to reciprocation of theslide changer to remove slides from stations which are about to receivefresh slides and to transport the thus removed slides into a collectingreceptacle wherein the slides are stacked in the same order in whichthey are being removed from the tray.

T T 'MEDAPmaIm 3574454 I SNEETIUFZ INVENTOR.

KARL DEEG BY m l pl K100 Illa/n7 supra PROJECTOR BACKGROUND OF THEINVENTION character, slides are removed from a stack and are transportedalternately to the two projecting stations. While the slide changermoves a slide from the stack toward one of the stations, it also expelsa slide from the other projecting station. The thus expelled slide mustbe withdrawn by hand and is thereupon placed onto a stack wherein theslides are accumulated in the same sequence in which their images arebeing projected onto the screen. A slide projector of the aforementionedtype is described in the US. Pat. No. 3,093,030.

SUMMARY OF THE INVENTION One of the objects of my invention is toprovide a slide projector which defines two projecting stations withnovel and improved means for transporting slides to such stations andwith novel means" for evacuating slides from the stations to provideroom for fresh slides.

Another object of the invention is to provide a slide projector whereinslides-are automatically stacked in the same sequence in which theirimages are being projected onto a screen.

A further object of the invention is to provide a novel slide changingand slide evacuating mechanism for use in projectors of the aboveoutlined character.

The improved slide projector comprises a pair of locating means disposedin a first plane and defining a first and a second projecting station, asupport located in a second plane between the two stations and arrangedto carry the lowermost or foremost slide of a supply of stacked slideswhich can be stored in a magazine or tray, movable slide changer meanscomprising slide transporting means located in or adjacent to the secondplane to respectively transport the foremost slide and thenext-following slide from the support into registry with the first andsecond stations in response to movement in a first and a seconddirection, and guide means for moving the thus transported slides fromthe second plane into the first plane.

The novel evacuating means comprises two evacuating portions or membersfor respectively removing slides from registry with the first and secondstations in response to movement of the transporting means'in the firstand second directions and for delivering the thus removed slides into areceptacle or tray wherein the slides accumulate in the same sequence inwhich they are removed from the magazine.

The operative connection between the slide changer means and theevacuating means may comprise two racks which are respectively providedon the slide changer means and evacuating means, and a pinion which isrotatable about a fixed axis and meshes with the two racks. The pinionmay be rotated by hand, by means of a reversible motor or in response tomanually or motorically induced reciprocation of one of the racks.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims.

The improved slide projector itself, however, both as to itsconstruction and its mode of operation, together with additionalfeatures and advantages thereof, will be best understood upon perusal ofthe following detailed description of certain specific embodiments withreference to the accompanying drawing.

FIG. I is a fragmentary perspective view of a slide projector whichembodies the invention; and

FIG. 2 is a vertical sectional view as seen in the direction of arrowsfrom the line II-Il of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 illustrate amagazine or trays 1 (shown by phantom lines) which accommodates a supplyof stacked slides 2. Two parallel strips 3 constitute a support for thelowermost slide 2 in the magazine 1; these strips are shown as beinglocated in a horizontal plane at a level at least slightly above afurther horizontal plane for two projecting stations respectivelydefined by pairs of locating strips 7, 8 disposed at the opposite sidesof the tray 1. The slide changer 4 has a slide transporting bar 16 whichis reciprocable slightly below the plane of the strips 3 and serves todeliver successive slides 2 alternately to the two projecting stations.The bar 16 has two elongated edge portions or shoulders 5, 5a the formerof which can transport a slide from the strips 3 toward the strips 7 andthe latter of which can deliver a slide from the strips 3 toward thestrips 8 when the slide changer 4 respectively moves in the directionsindicated by arrows A and B. The bar 16 is further provided with twolongitudinally spaced roofshaped lifting projections 6 which raise thestack of slides above the lowermost slide 2 in the tray I to reducefriction between the lowermost slide (which is being transported by theedge portion 5 or 50) and the adjoining next-to-thelowermost slide.

The guide means for moving slides 2 from the plane of the strips 3 intothe plane of the strips 7 and 8 comprises two pairs of leaf springs 9,10 which perform the additional function of urging the frames of slidesagainst the strips 7, 8 when such slides reach the respective projectingstations. FIG. 1 illustrates two slides 2a, 2b which are respectivelylocated at the left-hand and right-hand projecting station and arebiased against the strips 7, 8 by springs 9, 10.

The frame of the slide projector comprises two bearing blocks 11, 12which support the ends of an elongated guide rod 13 for a carriage 14 ofthe slide changer 4. The carriage 14 constitutes an elongated rack whichis in mesh with a pinion 17 whose shaft 18 is mounted in the frame ofthe projector. The slide changer 4 further comprises a handle 15 whichcan be reciprocated by hand in directions indicated by arrows A and B tothereby move slides 2 from the magazine 1 to the projecting stationsaccommodating the locating strips 7 and 8. The carriage 14 is rigid orintegral with the bar 16.

The pinion 17 is in mesh with a second rack 19 which fonns part of aslide evacuating or removing device 20. The latter comprises twoparallel elongated slots 21, 22 for fixed guide pins 23, 24 carried bythe frame of the projector. The rack 19 is connected to the centralportion of a leaf spring 25 whose end portions 26, 27 respectively carryevacuating members or pushers 29, 28. These pushers respectivelycomprise sloping cam faces 31, 30 which enable them to bypass slides inprojecting positions and shoulders or edge faces 33, 32 which entrainslides from projecting positions toward and into a collecting receptacle34 which is placed into the projector at a level below the tray 1.

The operation is as follows:

In the first step, the user places a tray 1 into the projector so thatthe lowermost slide 2 in the tray rests on the support including thestrips 3. Such slide is then located in a horizontal plane at a levelabove the plane of the projecting stations (strips 7 and 8), In the nextstep, the slide changer 4 is moved in the direction indicted by arrow A(by way of the handle 15) whereby the edge portion 5 of the bar 16engages the frame of the lowermost or outermost slide 2 in the tray 1and causes such slide to travel along the strips 3 and into the range ofthe leaf springs 9 which move the slide into the lefthand projectingstation and clamp the frame of such slide against the locating strips 7.While the bar 16 travels below the tray 1, its projections 6 raise thenext-to-thelowermost slide 2 to reduce friction between the slide whichis being transported by the edge portion 5 and the remainder of thestack in the tray 1.

The evacuating device 20 is caused to move in response to movement ofthe slide changer 4 but in the opposite direction (arrow C in FIG. 1).If the left-hand projecting station of FIG. I is empty when the slidechanger 4 transports a slide 2 toward the locating strips 7, the pusher28 of the evacuating device 20 simply travels toward the tray 1 but doesnot transport a slide into the receptacle However, if a slide (2a) isheld by the springs 9 and locating strips 7 at the left-hand projectingstation when the slide changer 4 transports a slide from the tray 1(arrow A), the shoulder 32 of the pusher 28 causes the slide 2a toadvance in the direction indicated by arrow C and to provide room forthe slide 2 which is being transported by the edge portion 5 of the bar16. The slide 20 is free to descend into the receptacle 34 by gravitynot later than at the time when the slide transported by the edgeportion 5 reaches the left-hand projecting station of FIG. 1.

If the right-hand projecting station of FIG. 1 accommodates a slide (2b)while the edge portion 5 of the bar 16 transports a slide 2 onto thestrips 7, the position of the slide 2b remains unchanged so that itsimage can be projected onto a screen. As stated before, the evacuatingdevice 20 moves in the direction indicated by arrow C when the slidechanger 4 moves in the direction indicated by arrow A; the cam face 31of the pusher 29 then slides along the frame of the slide 2b and causesthe end arrow D. 26 of leaf spring 25 to undergo a certain deformationwhich suffices to permit movement of the pusher 29 to strips right ofand beyond the slide 2b. The deformation of the end portion 26 is slidewhen the pusher 29 advances beyond the slide 2b.

When the projection of the image of the slide 2b is terminated, theoperator moves the slide changer 4 in the direction indicated by arrow Bwhereby the pinion 17 causes the evacuating device 20 to move in thedirection indicated by arrow D. The edge portion 5a transports thelowermost slide 2 from the tray 1 along the support including the strips3 and toward the locating strips 8 while the shoulder 33 of the pusher29 transports the slide 2b toward the receptacle 34. The sloping camface 30 of the pusher 28 engages the slide resting on the locatingstrips 7 and causes some deformation of the end portion 27 of the leafspring 25. The slide 212 descends into the receptacle 34 and comes torest on the slide 20. Thus, the slides are stacked in the receptacle 34in the same sequence in which they are being removed from the tray 1.

An important advantage of the projector which embodies the structureshown in FIGS. 1 and 2 is that its optical system can project the imagesof two slides at a time. Thus, and referring to FIG. I, the images ofslides 24, 2b can be projected simultaneously. Of course, it is equallypossible to project the image of one slide at a time. The projector isequipped with shutter means (not shown) which can prevent passage oflight through one of the slides 2a, 2b while the image of the otherslide is being projected onto a screen. When the projection of images ofall slides is completed, the receptacle 34 can be removed from theprojector and can be used for renewed projection of images in the samesequence. The evacuated tray 1 is then placed into the positionpreviously occupied by receptacle 34. Aside from the manual shifting ofslide changer 4, the operation of the slide projector shown in FIGS. 1and 2 is analogous to that of a fully automatic projector. All that theoperator has to do is to place a loaded tray 1 into the projector, toplace an empty receptacle 34 below the tray 1, and to move the slidechanger 4 back and forth in order to change the slides at the twoprojecting stations.

It is clear that the improved projector and its slide changing,evacuating and stacking parts can be modified in a number of wayswithout departing from the spirit of the invention. For example, and asindicated in FIG. 2, the shaft 18 of the pinion 17 can be coupled to theoutput shaft of a reversible electric motor 20. Alternatively, the motor30 or another suitable motor can drive the handle of the slide changer 4by way of a crank drive, eccentric or another transmission. The motor 30can be disconnected from the shaft 18 when the operator wishes tomanipulate the slide changer 4 by hand. Also, the transmission 14, l7,19 can be replaced by a linkage, a train of gears or the like.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of my contribution to the art and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

lclaim:

1. In a slide projector, a combination comprising a pair of locatingmeans disposed in a first plane and defining a first and a spaced secondprojecting station; a support located in a second plane between saidlocating means and arranged to carry an outermost slide of a supply ofstacked slides; movable slide changer means comprising slidetransporting means located in said second plane to respectivelytransport the outermost slide and the next-following slide from saidsupport into registry with the first and second stations in response tomovement in a first and a second direction; guide means for moving thethus transported slides from said second into said first plane; andevacuating means comprising two evacuating members for respectivelyremoving slides from registry with said first and second stations inresponse to movement of said transporting means in said first and seconddirections, and resilient means supporting said evacuating members.

2. A combination as defined in claim I, wherein each of said evacuatingmembers comprises a pusher having a cam face which enables it to bypassa slide at the respective projecting station in response to movement ofthe pusher in the direction in which the transporting means advances inorder to transport a slide from said support to the respective station.

3. In a slide projector, a combination comprising a pair of locatingmeans disposed in a first plane and defining a first and a spaced secondprojecting station; a support located in a second plane between saidlocating means and arranged to carry the outermost slide of a supply ofstacked slides, said outermost slide constituting the lowermost slide ofsaid supply; movable slide changer means comprising slide transportingmeans located in said second plane to respectively transport thelowermost slide and the nextfollowing slide from said support intoregistry with the first and second stations in response to movement in afirst and a second direction, and means for lifting the remainder of thesupply of stacked slides with reference to the lowermost slide inresponse to movement of said transporting means in either one of saiddirections; guide means for moving the thus transported slides from saidsecond into said first plane; and evacuating means comprising twoevacuating members for respectively removing slides from registry withsaid first and second stations in response to movement of saidtransporting means in said first and second directions.

4. A combination as defined in claim 3, wherein said transporting meanscomprises two motion transmitting portions one of which transportsslides to the one and the other of which transports slides to the otherof said stations.

5. In a slide projector, a combination comprising a pair of locatingmeans disposed in a first plane and defining a first and a spaced secondprojecting station; a support located in a second plane between saidlocating means and arranged to carry an outermost slide of a supply ofstacked slides; movable slide changer means comprising slidetransporting means located in said second plane to respectivelytransport the outermost slide and the next-following slide form saidsupport into registry with the first and second stations in response tomovement in a first and a second direction; guide means for moving thethus transported slides from said second into said first plane;evacuating means comprising two evacuating member for respectivelyremoving slides from registry with said first and second stations inresponse to movement of said transporting means in said first and seconddirections, said slide changer means and said evacuating means beingrespectively provided with first and second racks; and pinion meansrotatable about a predetermined axis and meshing with said racks so thatone of said racks is moved in one direction in response to movement ofthe other rack in the other direction and vice versa.

6. A combination as defined in claim 5, wherein said first plane islocated at a level below said second plane.

7. A combination asdefined in claim 5, further comprising means forcollecting slides removed by said evacuating members in the samesequence in which the slides are being removed from said support.

8. A combination as defined in claim 5, wherein said guide meanscomprises resilient elements.

9. A combination as defined in claim 5, further comprising motor meansfor rotating said pinion means.

10. A combination as defined in claim 5, wherein said slide changermeans comprises handle means by means of which said slide changer meansis movable in said directions.

11. A combination as defined in claim 5, wherein said slide changermeans is reciprocable in a substantially horizontal plane and saidsupport is arranged to carry a tray containing a stack of horizontalslides the lowermost one of which rests on said support in the path ofmovement of said transporting means.

12. A combination as defined in claim 11, further comprising a removablereceptacle located at a level below said support and arranged to collectslides which are removed from said stations by said evacuating memberswhereby the thus removed slides enter the receptacle by gravity feed.

13. A combination as defined in claim 5, further comprising transmissionmeans connecting said evacuating means to said slide changer means formovement in said second direction on movement of said slide changermeans in said first direction, and vice versa.

1. In a slide projector, a combination comprising a pair of locatingmeans disposed in a first plane and defining a first and a spaced secondprojecting station; a support located in a second plane between saidlocating means and arranged to carry an outermost slide of a supply ofstacked slides; movable slide changer means comprising slidetransporting means located in said second plane to respectivelytransport the outermost slide and the next-following slide from saidsupport into registry with the first and second stations in response tomovement in a first and a second direction; guide means for moving thethus transported slides from said second into said first plane; andevacuating means comprising two evacuating members for respectivelyremoving slides from registry with said first and second stations inresponse to movement of said transporting means in said first and seconddirections, and resilient means supporting said evacuating members.
 2. Acombination as defined in claim 1, wherein each of said evacuatingmembers comprises a pusher having a cam face which enables it to bypassa slide at the respective projecting station in response to movement ofthe pusher in the direction in which the transporting means advances inorder to transport a slide from said support to the respective station.3. In a slide projector, a combination comprising a pair of locatingmeans disposed in a first plane and defining a first and a spaced secondprojecting station; a support located in a seCond plane between saidlocating means and arranged to carry the outermost slide of a supply ofstacked slides, said outermost slide constituting the lowermost slide ofsaid supply; movable slide changer means comprising slide transportingmeans located in said second plane to respectively transport thelowermost slide and the next-following slide from said support intoregistry with the first and second stations in response to movement in afirst and a second direction, and means for lifting the remainder of thesupply of stacked slides with reference to the lowermost slide inresponse to movement of said transporting means in either one of saiddirections; guide means for moving the thus transported slides from saidsecond into said first plane; and evacuating means comprising twoevacuating members for respectively removing slides from registry withsaid first and second stations in response to movement of saidtransporting means in said first and second directions.
 4. A combinationas defined in claim 3, wherein said transporting means comprises twomotion transmitting portions one of which transports slides to the oneand the other of which transports slides to the other of said stations.5. In a slide projector, a combination comprising a pair of locatingmeans disposed in a first plane and defining a first and a spaced secondprojecting station; a support located in a second plane between saidlocating means and arranged to carry an outermost slide of a supply ofstacked slides; movable slide changer means comprising slidetransporting means located in said second plane to respectivelytransport the outermost slide and the next-following slide form saidsupport into registry with the first and second stations in response tomovement in a first and a second direction; guide means for moving thethus transported slides from said second into said first plane;evacuating means comprising two evacuating member for respectivelyremoving slides from registry with said first and second stations inresponse to movement of said transporting means in said first and seconddirections, said slide changer means and said evacuating means beingrespectively provided with first and second racks; and pinion meansrotatable about a predetermined axis and meshing with said racks so thatone of said racks is moved in one direction in response to movement ofthe other rack in the other direction and vice versa.
 6. A combinationas defined in claim 5, wherein said first plane is located at a levelbelow said second plane.
 7. A combination as defined in claim 5, furthercomprising means for collecting slides removed by said evacuatingmembers in the same sequence in which the slides are being removed fromsaid support.
 8. A combination as defined in claim 5, wherein said guidemeans comprises resilient elements.
 9. A combination as defined in claim5, further comprising motor means for rotating said pinion means.
 10. Acombination as defined in claim 5, wherein said slide changer meanscomprises handle means by means of which said slide changer means ismovable in said directions.
 11. A combination as defined in claim 5,wherein said slide changer means is reciprocable in a substantiallyhorizontal plane and said support is arranged to carry a tray containinga stack of horizontal slides the lowermost one of which rests on saidsupport in the path of movement of said transporting means.
 12. Acombination as defined in claim 11, further comprising a removablereceptacle located at a level below said support and arranged to collectslides which are removed from said stations by said evacuating memberswhereby the thus removed slides enter the receptacle by gravity feed.13. A combination as defined in claim 5, further comprising transmissionmeans connecting said evacuating means to said slide changer means formovement in said second direction on movement of said slide changermeans in said first direction, and vice versa.